feat(fleet): enrich host_info_json (chip, hostname, boot time, pid, disks, LAN IPs)

[PeronGH]

Closes RUN-42
(all three asks — chip as cpu_model, disk capacity as disks[].total_bytes, LAN IP as lan_ips[]).

Summary

• Adds descriptive host facts to host_info_json in the fleet agent's enroll/attach payloads:
  • cpu_model — CPU brand string
  • hostname — kernel hostname (distinct from machine_name)
  • boot_time_unix / agent_pid — diagnostic anchors
  • disks[] — static disk list (name, mount_point, file_system, total_bytes; no live free-space)
  • lan_ips[] — every non-loopback, non-unspecified IP across all interfaces (interface, ip, prefix; both v4 and v6)
• Keeps the split honest: nothing added here influences placement — decision inputs remain in HostTelemetry (live memory / load / cpu count). Deliberately omits available_space, FD counts, and other live-load signals for the same reason.
• Wire-shape stable: host_info_json is a free-form string; no .proto change, no protobuf-breaking migration.

Test plan

• cargo check -p arcbox-fleet-agent
• cargo clippy -p arcbox-fleet-agent --all-targets -- -D warnings
• cargo test -p arcbox-fleet-agent host:: (9 pass — existing capability-mapping tests unaffected)
• Observed via a live enroll/attach roundtrip against the fleet gateway (JSON contains all new keys on macOS and Linux, with meaningful lan_ips on a multi-NIC host)

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[pullfrog]

The check suite failed on the Check formatting step (cargo fmt --check). The PR's new hostname assignment in fleet/arcbox-fleet-agent/src/host.rs was split across three lines, but rustfmt collapses it onto one. I collapsed it to a single line, verified cargo fmt --check passes cleanly, then committed and pushed to the PR branch.

  ^{｜ View workflow run ｜ via Pullfrog ｜ Using Claude Opus ｜ 𝕏}

[pullfrog]

✅ No new issues found.

Reviewed changes — enriches the fleet agent's free-form host_info_json blob with descriptive host facts, verified for API correctness, call-site cost, and dependency availability.

• Add descriptive host facts to host_info_json — cpu_model (first CPU brand after refresh_cpu_all), nullable hostname, boot_time_unix, agent_pid, and a static disks array (name/mount_point/file_system/total_bytes).
• Descriptive-only split preserved — no placement-influencing signals added here; live decision inputs stay in HostTelemetry, matching the updated doc comment.
• No wire change — host_info_json remains a free-form string; no .proto edit, no protobuf-breaking migration.

Notes from the review, none blocking:

• host_info_json() is invoked only at enroll.rs:79 and attach.rs:356, and the attach.rs comment confirms host facts are constant for the process lifetime (sent once per connection, not per heartbeat), so the fresh System::new() + CPU/disk refresh is not a hot-path cost.
• The sysinfo 0.33 API usage (refresh_cpu_all, Disks::new_with_refreshed_list, Cpu::brand, the Disk accessors, and the static System::{name,long_os_version,kernel_version,boot_time} calls) is correct, and hostname/sysinfo/serde_json are all already declared dependencies.
• The hostname field falls back to null here while the top-level machine_name() falls back to "unknown" — an intentional and harmless difference (JSON null is the honest representation of "couldn't determine").

  ^{｜ View workflow run ｜ Using Claude Opus ｜ 𝕏}

[linear-code]

RUN-42

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[pullfrog]

✅ No new issues found.

Reviewed changes — since the prior pullfrog approval at 4e226657, the delta is a rustfmt tweak plus a new lan_ips field added to the fleet agent's free-form host_info_json blob.

• Add lan_ips[] to host_info_json — enumerates every non-loopback, non-unspecified IP across all interfaces via sysinfo::Networks::new_with_refreshed_list(), emitting interface/ip/prefix for both v4 and v6.
• rustfmt on hostname assignment — no behavior change (74451dca).

Notes from the review, none blocking:

• sysinfo = "0.33" is pulled with default features, which include network, so Networks and NetworkData::ip_networks() compile; IpNetwork exposes public addr: IpAddr and prefix: u8 in 0.33, so the field usage is correct.
• The !is_loopback() && !is_unspecified() filter matches the described intent. IPv6 link-local (fe80::) addresses are included since they are neither loopback nor unspecified — intentional per the PR description ("both v4 and v6") and harmless for descriptive-only telemetry.
• Consistent with the rest of the function: no wire/proto change, still a free-form string sent once per connection attempt (not per heartbeat), so no hot-path cost.

  ^{｜ View workflow run ｜ Using Claude Opus ｜ 𝕏}

[greptile-apps]

Greptile Summary

This PR enriches the fleet agent host metadata sent during enrollment and attachment. The main changes are:

• Adds cpu_model, hostname, boot_time_unix, and agent_pid to host_info_json.
• Adds static disk metadata with name, mount point, file system, and total bytes.
• Adds LAN IP entries from refreshed network interfaces.
• Keeps placement inputs separate in HostTelemetry.

Confidence Score: 5/5

Safe to merge with minimal risk.

The change is localized to a free-form metadata builder and keeps placement-critical telemetry unchanged.

No files require special attention.

T-Rex Logs

What T-Rex did

• I reviewed the protoc-check log and confirmed protoc lookup failed with exit code 127.
• I examined the cargo-check-arcbox-fleet-agent.log and found cargo check failing in arcbox-protocol build.rs due to missing protoc.
• I checked the cargo-clippy-arcbox-fleet-agent.log and confirmed clippy is not installed for the toolchain.
• I reviewed the cargo-test-arcbox-fleet-agent-host.log and rerun log, noting the host test was attempted before timeout/build locking.
• I looked at the host-info-shape-source-check.log and saw a fallback confirmation that the changed host JSON fields are present in the function body.

_{Ran code and verified through T-Rex}

Important Files Changed

Filename	Overview
fleet/arcbox-fleet-agent/src/host.rs	Expands host_info_json with descriptive CPU, hostname, boot time, agent PID, disk inventory, and LAN IP metadata without changing telemetry placement inputs.

Sequence Diagram

%%{init: {'theme': 'neutral'}}%%
sequenceDiagram
participant Agent as Fleet agent
participant Host as host_info_json()
participant Sysinfo as sysinfo/hostname APIs
participant Gateway as Fleet gateway

Agent->>Host: build enroll/attach payload
Host->>Sysinfo: collect OS, CPU, hostname, boot time, PID, disks, LAN IPs
Sysinfo-->>Host: best-effort host facts
Host-->>Agent: JSON string
Agent->>Gateway: EnrollRequest/Attach(host_info_json)
Note over Agent,Gateway: Placement inputs remain in HostTelemetry heartbeats

Loading

%%{init: {'theme': 'base', 'themeVariables': {"darkMode": true, "background": "#0d1117", "primaryColor": "#21262d", "primaryTextColor": "#e6edf3", "primaryBorderColor": "#8b949e", "lineColor": "#8b949e", "textColor": "#e6edf3", "edgeLabelBackground": "#161b22", "actorBkg": "#21262d", "actorBorder": "#8b949e", "actorTextColor": "#e6edf3", "actorLineColor": "#8b949e", "signalColor": "#8b949e", "signalTextColor": "#e6edf3", "noteBkgColor": "#373320", "noteBorderColor": "#d4a72c", "noteTextColor": "#f0e6c0", "labelBoxBkgColor": "#21262d", "labelBoxBorderColor": "#8b949e", "labelTextColor": "#e6edf3", "loopTextColor": "#e6edf3", "activationBkgColor": "#30363d", "activationBorderColor": "#8b949e"}}}%%
sequenceDiagram
participant Agent as Fleet agent
participant Host as host_info_json()
participant Sysinfo as sysinfo/hostname APIs
participant Gateway as Fleet gateway

Agent->>Host: build enroll/attach payload
Host->>Sysinfo: collect OS, CPU, hostname, boot time, PID, disks, LAN IPs
Sysinfo-->>Host: best-effort host facts
Host-->>Agent: JSON string
Agent->>Gateway: EnrollRequest/Attach(host_info_json)
Note over Agent,Gateway: Placement inputs remain in HostTelemetry heartbeats

Loading

_{Reviews (1): Last reviewed commit: "feat(fleet): add lan_ips to host_info_js..." | Re-trigger Greptile}